Method for producing a multimetallic sulfureous solid and use thereof as a catalyst in a method for producing higher alcohols from synthesis gas

Abstract

The present invention relates to a sulphided multi-metallic catalyst, a process for obtaining it by preparing a metal mixture and subsequent sulphidation thereof and its use in a process for producing higher alcohols (C 2+ ), mainly ethanol, through the catalytic conversion of synthesis gas.

1 . A process for obtaining a sulphurated multi-metallic catalyst comprising the components C(i)C(ii) x C(iii) y , characterised in that it comprises at least the following stages:
 a) Combining and reacting at least one compound of C(i) with at least one compound of C(ii) and with at least one compound of C(iii) to obtain a solid;   b) Activating and sulphurating the solid obtained;   
       being,
 C(i) a component (i) selected from the list comprising molybdenum (Mo), tungsten (W) and any combination thereof, 
 C(ii) a component (ii) selected from the list of elements comprising at least one element belonging to groups 7 to 14 of the periodic table and any combination thereof, 
 C(iii) a component (iii) selected from the list of elements comprising groups 1 and 2 of the periodic table, lanthanides and any combination thereof, 
 “x” and “y” the mole ratios of C(ii) and C(iii) with respect to C(i), respectively, “x” being comprised between 0.1-10 and “y” between 0.2-10. 
 
     
     
         2 . The process according to  claim 1 , wherein C(i) comprises at least Mo. 
     
     
         3 . The process according to any of  claim 1  or  2 , wherein C(ii) comprises at least Co, Ni or any combination thereof. 
     
     
         4 . The process according to  claim 3 , wherein C(ii) also comprises at least one element selected from the list that comprises Re, Ru, Rh, Ir, Zn, Ga, In, Ge, Sn, La, Sm and any combination thereof. 
     
     
         5 . The process according to any of  claims 1  to  4 , wherein C(iii) comprises Li, Na, K, Rb, Cs or any combination thereof. 
     
     
         6 . The process according to  claim 5 , wherein C(iii) comprises K, Cs or any combination thereof. 
     
     
         7 . The process according to any of the preceding claims, characterised in that the sulphuration stage is carried out by exposing the solid to a gas stream that comprises at least one sulphurated component. 
     
     
         8 . The process according to  claim 7 , characterised in that the sulphurated compound is selected from the list that comprises: a compound with the formula R 1 R 2 S, wherein R 1  and R 2  may be identical or different therebetween and are selected from among hydrogen, alkyl (C 1 -C 6 ) or aryl; thiophenes; mercaptans, carbonyl sulphide; and any combination thereof. 
     
     
         9 . The process according to any of  claims 7  and  8 , wherein the gas stream also comprises a gas selected from among H 2 , N 2 , noble gas, synthesis gas and any combination thereof. 
     
     
         10 . The process according to any of  claims 7  to  9 , wherein the molar proportion of the sulphurated compound in the gas stream is between 1% and 85%. 
     
     
         11 . The process according to  claim 10 , wherein the molar proportion of the sulphurated compound in the gas stream is comprised between 6% and 20%. 
     
     
         12 . The process according to any of the preceding claims, wherein the sulphuration temperature is comprised between 200° C. and 750° C. 
     
     
         13 . The process according to  claim 12 , wherein the sulphuration temperature is comprised between 300° C. and 600° C. 
     
     
         14 . The process according to any of the preceding claims, characterised in that the mole ratio “x” is comprised between 0.2 and 2. 
     
     
         15 . The process according to any of the preceding claims, wherein at least 60% of the molar mass of C(ii) is selected from among Co, Ni and any combination thereof. 
     
     
         16 . The process according to any of the preceding claims, wherein the mole ratio “y” is comprised between 0.1 and 4. 
     
     
         17 . The process according to  claim 16 , wherein the mole ratio “y” is comprised between 0.3 and 1.5. 
     
     
         18 . The process according to any of the preceding claims, characterised in that the catalyst also comprises at least one element selected from among carbon, nitrogen and combinations thereof. 
     
     
         19 . The process according to  claim 18 , wherein the ratio between the moles of carbon and the moles of C(i) is less than 3. 
     
     
         20 . The process according to any of the preceding claims, characterised in that activation of the solid in stage (b) is carried out by means of a thermal treatment. 
     
     
         21 . The process according to  claim 20 , characteristed in that activation is carried out at a temperature between 200° C. and 700° C. 
     
     
         22 . The process according to  claim 21 , characterised in that activation is carried out at a temperature comprised between 250° C. and 550° C. 
     
     
         23 . The process according to any of  claims 20  to  22 , wherein the activation stage is carried out under a sulphur-free gas stream. 
     
     
         24 . The process according to  claim 23 , wherein the gas stream comprises air, N 2 , noble gas, H 2 , synthesis gas or any combination thereof. 
     
     
         25 . The process according to any of the preceding claims, wherein stage (a) is carried out in an aqueous medium, the solid is obtained by precipitation and is separated before stage (b). 
     
     
         26 . The process according to  claim 25 , wherein precipitation is carried out by adjusting the temperature, pH, solvent volume or any combination thereof. 
     
     
         27 . The process according to any of  claims 25  and  26 , wherein precipitation of the solid is carried out in stage (a) by adjusting the temperature and removing the solvent by evaporation of an aqueous solution comprising the compound of C(i), the compound of C(ii) and the compound of C(iii). 
     
     
         28 . The process according to any of  claims 25  and  26 , wherein precipitation is carried out in stage (a) by adjusting the temperature and pH of an aqueous solution comprising the compound of C(i), prior to combining with the compound of C(ii) and the compound of C(iii). 
     
     
         29 . The process according to any of  claims 25  and  26 , wherein precipitation is carried out in stage (a) by adjusting the temperature and pH of an aqueous solution comprising the compound of C(i) and the compound of C(iii), prior to combining with the compound of C(ii). 
     
     
         30 . The process according to  claims 25  and  26 , wherein the pH of an aqueous solution comprising the compound of C(i) is adjusted in stage (a) by adding the compound of C(iii), prior to combining with the compound of C(ii). 
     
     
         31 . The process according to any of  claims 26  to  30 , wherein the pH is adjusted to between 8 and 13. 
     
     
         32 . The process according to any of  claims 26  to  31 , wherein the pH is adjusted by adding at least one compound selected from the list that comprises ammonia, ammonium hydroxide, organic amines, compounds which are thermally decomposed releasing ammonia and any combination thereof. 
     
     
         33 . The process according to any of  claims 25  to  32 , wherein the temperature is adjusted to between 50° C. and 120° C. in stage (a). 
     
     
         34 . The process according to any of the preceding claims, wherein the compound of C(i) is ammonium heptamolybdate, ammonium metatungstate or any combination thereof. 
     
     
         35 . The process according to any of the preceding claims, characterised in that the compound of C(ii) is a nitrate, chloride, carbonate, acetate or combinations thereof. 
     
     
         36 . The process according to any of the preceding claims, characterised in that the compound of C(iii) is a carbonate, hydroxycarbonate, acetate, acetylacetonate, citrate, nitrate, chloride or any combination thereof. 
     
     
         37 . The process according to any of the preceding claims, wherein additionally, in stage (a), a support is suspended in the liquid medium. 
     
     
         38 . The process according to  claim 37 , wherein the suspended support is a metal carbide, oxide, carbon or any combination thereof. 
     
     
         39 . The process according to  claim 38 , wherein the oxide is selected from the list that comprises a clay, SiO 2 , TiO 2 , Al 2 O 3 , ZrO 2 , lanthanide element oxide and any combination thereof. 
     
     
         40 . A catalyst obtainable by the process defined according to any one of the preceding claims. 
     
     
         41 . Use of the catalyst, according to  claim 40 , in a process for producing higher alcohols (C 2+ ) through the catalytic conversion of synthesis gas. 
     
     
         42 . Use of the catalyst, according to  claim 41 , wherein the higher alcohol (C 2+ ) is ethanol.